[chore] service: inject default views via settings (#13775)

#### Description

Instead of updating the telemetry config, pass the default views in via
settings and have the telemetry implementation use it as appropriate.
This is necessary to decouple the service package from the
otelconftelemetry config.

#### Link to tracking issue

Part of
https://github.com/open-telemetry/opentelemetry-collector/issues/4970

#### Testing

N/A, non-functional change.

#### Documentation

N/A

---------

Co-authored-by: Alex Boten <223565+codeboten@users.noreply.github.com>

service/service.go

@@ -124,14 +124,11 @@ func New(ctx context.Context, set Settings, cfg Config) (*Service, error) {
 	}
 
 	mpConfig := &cfg.Telemetry.Metrics.MeterProvider
-	if mpConfig.Views == nil {
-		mpConfig.Views = configureViews(cfg.Telemetry.Metrics.Level)
-	}
-
 	telFactory := otelconftelemetry.NewFactory()
 	telset := telemetry.Settings{
-		BuildInfo:  set.BuildInfo,
-		ZapOptions: set.LoggingOptions,
+		BuildInfo:    set.BuildInfo,
+		ZapOptions:   set.LoggingOptions,
+		DefaultViews: configureViews,
 	}
 
 	telProviders, err := telFactory.CreateProviders(ctx, telset, &cfg.Telemetry)

service/telemetry/otelconftelemetry/metrics_test.go

@@ -6,7 +6,9 @@ package otelconftelemetry
 import (
 	"context"
 	"fmt"
+	"io"
 	"net/http"
+	"net/http/httptest"
 	"testing"
 	"time"
 
@@ -20,6 +22,8 @@ import (
 	semconv "go.opentelemetry.io/otel/semconv/v1.26.0"
 
 	"go.opentelemetry.io/collector/config/configtelemetry"
+	"go.opentelemetry.io/collector/pdata/pmetric"
+	"go.opentelemetry.io/collector/pdata/pmetric/pmetricotlp"
 	"go.opentelemetry.io/collector/service/internal/promtest"
 	"go.opentelemetry.io/collector/service/telemetry"
 )
@@ -255,3 +259,91 @@ func TestInstrumentEnabled(t *testing.T) {
 	require.NoError(t, err)
 	assert.Implements(t, new(enabledInstrument), floatGauge)
 }
+
+func TestTelemetryMetrics_DefaultViews(t *testing.T) {
+	type testcase struct {
+		configuredViews    []config.View
+		expectedMeterNames []string
+	}
+
+	defaultViews := func(level configtelemetry.Level) []config.View {
+		assert.Equal(t, configtelemetry.LevelDetailed, level)
+		return []config.View{{
+			Selector: &config.ViewSelector{
+				MeterName: ptr("a"),
+			},
+			Stream: &config.ViewStream{
+				Aggregation: &config.ViewStreamAggregation{
+					Drop: config.ViewStreamAggregationDrop{},
+				},
+			},
+		}}
+	}
+
+	for name, tc := range map[string]testcase{
+		"no_configured_views": {
+			expectedMeterNames: []string{"b", "c"},
+		},
+		"configured_views": {
+			configuredViews: []config.View{{
+				Selector: &config.ViewSelector{
+					MeterName: ptr("b"),
+				},
+				Stream: &config.ViewStream{
+					Aggregation: &config.ViewStreamAggregation{
+						Drop: config.ViewStreamAggregationDrop{},
+					},
+				},
+			}},
+			expectedMeterNames: []string{"a", "c"},
+		},
+	} {
+		t.Run(name, func(t *testing.T) {
+			var metrics pmetric.Metrics
+			srv := httptest.NewServer(http.HandlerFunc(func(_ http.ResponseWriter, req *http.Request) {
+				body, err := io.ReadAll(req.Body)
+				assert.NoError(t, err)
+
+				exportRequest := pmetricotlp.NewExportRequest()
+				assert.NoError(t, exportRequest.UnmarshalProto(body))
+				metrics = exportRequest.Metrics()
+			}))
+			defer srv.Close()
+
+			cfg := createDefaultConfig().(*Config)
+			cfg.Metrics.Level = configtelemetry.LevelDetailed
+			cfg.Metrics.Views = tc.configuredViews
+			cfg.Metrics.Readers = []config.MetricReader{{
+				Periodic: &config.PeriodicMetricReader{
+					Exporter: config.PushMetricExporter{
+						OTLP: &config.OTLPMetric{
+							Endpoint: ptr(srv.URL),
+							Protocol: ptr("http/protobuf"),
+							Insecure: ptr(true),
+						},
+					},
+				},
+			}}
+
+			factory := NewFactory()
+			settings := telemetry.Settings{DefaultViews: defaultViews}
+			providers, err := factory.CreateProviders(t.Context(), settings, cfg)
+			require.NoError(t, err)
+
+			mp := providers.MeterProvider()
+			for _, meterName := range []string{"a", "b", "c"} {
+				counter, _ := mp.Meter(meterName).Int64Counter(meterName + ".counter")
+				counter.Add(t.Context(), 1)
+			}
+			require.NoError(t, providers.Shutdown(t.Context())) // should flush metrics
+
+			var scopes []string
+			for _, rm := range metrics.ResourceMetrics().All() {
+				for _, sm := range rm.ScopeMetrics().All() {
+					scopes = append(scopes, sm.Scope().Name())
+				}
+			}
+			assert.ElementsMatch(t, tc.expectedMeterNames, scopes)
+		})
+	}
+}

service/telemetry/otelconftelemetry/telemetry.go

@@ -121,10 +121,12 @@ func (t *otelconfTelemetry) Shutdown(ctx context.Context) error {
 	return nil
 }
 
-func newSDK(ctx context.Context, _ telemetry.Settings, cfg *Config, res *sdkresource.Resource) (*config.SDK, error) {
+func newSDK(ctx context.Context, set telemetry.Settings, cfg *Config, res *sdkresource.Resource) (*config.SDK, error) {
 	mpConfig := cfg.Metrics.MeterProvider
 	if cfg.Metrics.Level == configtelemetry.LevelNone {
 		mpConfig.Readers = nil
+	} else if mpConfig.Views == nil && set.DefaultViews != nil {
+		mpConfig.Views = set.DefaultViews(cfg.Metrics.Level)
 	}
 
 	// Merge the BuildInfo-based resource attributes with the user-defined resource attributes.

service/telemetry/telemetry.go

@@ -6,6 +6,7 @@ package telemetry // import "go.opentelemetry.io/collector/service/telemetry"
 import (
 	"context"
 
+	otelconf "go.opentelemetry.io/contrib/otelconf/v0.3.0"
 	"go.opentelemetry.io/otel/log"
 	nooplog "go.opentelemetry.io/otel/log/noop"
 	"go.opentelemetry.io/otel/metric"
@@ -15,6 +16,7 @@ import (
 	"go.uber.org/zap"
 
 	"go.opentelemetry.io/collector/component"
+	"go.opentelemetry.io/collector/config/configtelemetry"
 	"go.opentelemetry.io/collector/pdata/pcommon"
 	"go.opentelemetry.io/collector/service/telemetry/internal/migration"
 )
@@ -67,6 +69,16 @@ type Settings struct {
 
 	// ZapOptions contains options for creating the zap logger.
 	ZapOptions []zap.Option
+
+	// DefaultViews holds a function that returns default metric
+	// views for the given internal telemetry metrics level.
+	//
+	// The meter provider is expected to use this if no user-provided
+	// view configuration is supplied.
+	//
+	// TODO we should not use otelconf.View directly here, change
+	// to something independent of otelconf.
+	DefaultViews func(configtelemetry.Level) []otelconf.View
 }
 
 // Factory is a factory interface for internal telemetry.